The present invention relates to a device for introducing rolled-steel sections into a cold shear or straightening machine after the sections have been collected into layers behind cooling beds. In these devices the layers of sections transported on a roller path in front of the straightening or shear machine are held down by a profiled hold-down roll, and are transported by a holding device which is moveable in the longitudinal direction of the section. The holding device hangs above the roller path and has a lift magnet with profiled ledges, capable of transporting the sections to the driver/entry point of the cold shear or strengthening machine in synchronism with the speed of transport of the roller path.
Operators of these devices are now increasingly requiring an automatic threading means for feeding and threading the pre-collected packages of metallic bars or profiles into the cold shear or straightening machines. A plant of this type is described in Federal Republic of Germany 38 18 745 A1, FIG. 7.
If the threading device of the above type is not used in combination with the upstream devices for holding the bars during the entire cooling process but if they are introduced or retrofitted, for instance, subsequently into existing downstream processing machines, there is the added problem of rearranging uneven bar packages so that a proper taking over of the profiles by the lifting magnet as well as the subsequent introduction of the bars into the shear or straightening machine is assured. In addition, there is the added requirement that upon the transportation of the bars, the speed of the lift magnet which holds the bar ends and the speed of the roller path are so adapted to each other that the bars are not accelerated or decelerated with respect to the magnet by the friction against the rollers of the roller path. If this were to occur the bars would shift with respect to each other or drop out.